These Bags are Cost effective and meet FDA specifications for direct food contact. No heat sealing needed, they have an easy peel off strip and fold with ease. BOPP Resealable bags are 160 guage for high clarity, also acid-free with no harmful plasticizers used in production. They are chemically non-aggressive which makes them more suitable for long term archiving, Archival safe and Resists moisture. Bio-orienting gives the bags breathing properties.